35 results about "Critical point drying" patented technology

A fluid flow control valve comprises (a) a high pressure region adapted to contain a fluid at its supercritical or nearcritical temperature and pressure conditions and connected via an orifice to a low pressure region, (b) a seat adjacent the orifice, (c) a sealing element positionable against the seat to form a seal between the high pressure region and the low pressure region, and (d) an electrically and / or electronically controlled actuator operable to move the sealing element against and / or away from the seat to allow control of fluid flow from the high pressure region to the low pressure region. In a specific embodiment, the high pressure region contains a fluid at its supercritical or nearcritical temperature and pressure conditions. The valve may be used, for example, to provide very low flow rates, for example, for supercritical fluid chromatography, supercritical fluid extraction, critical point drying, supercritical fluid cleaning, and supercritical fluid separation methods. In another embodiment, the valve is suitable for use in methods of delivering a biologically active substance to a patient in need thereof.

Methods for increasing osteoinductivity and / or surface area of bone material are provided. The methods include providing bone material and dehydrating the bone material with a solvent at its critical point. A useful solvent for critical point dehydrating is carbon dioxide. Critical point dehydration resulting in increased osteoinductivity and / or surface area can be applied to many types of bone material including bone particles, bone chips, bone fibers, bone matrices, both demineralized and non-demineralized. An implantable composition having an enhanced osteoinductivity and / or osteoconductivity is also provided. The implantable composition contains demineralized bone matrix dried at critical point of carbon dioxide. Critical point dried fibers of a demineralized bone matrix have a BET value from about 40 m2 / gm to about 100 m2 / gm, a value that is 100 times higher than corresponding vacuum dried or lyophilized DBM fibers.

Multipurpose holders for electronic components utilized during a fabrication process must allow the components to be submerged into baths of hydrofluoric acid, rinsed in de-ionized water (D.I.), placed into baths of alcohol for dehydration, and ultimately dried prior to further processing. The holders provide both fluid flow around the wafers while in each bath of fluid and while being processed by the critical point dryer, and a containment system to keep the wafer submerged in fluid at all times during the transfer between baths and the drying equipment.

The disclosed preparation method for ovum of sea fish as TEM sample comprises: fixing fresh fish ovum by glutaral solution diluted by phosphate buffer, cleaning, dewatering the ovum by 20-70% alcohol with concentration gradient increased by 10% and 75-100% alcohol with concentration gradient increased by 5% as two stages, then dewatering in pure acetone with CaCl2 as agent; then, drying at critic point, and spraying gold for the sample. This invention has ovum completion rate as 93.8-96.7% with low cost and convenient operation.

The invention discloses a scanning electron microscope sample processing method for head sensory appendages of white ants. The method comprises the steps of putting white ants into a specially-made wind washing device, carrying out wind washing, feeding the white ants into a specially-made auxiliary vacuumizing device, carrying out vacuumizing operation to sink the white ants, carrying out front fixing and dissection, sequentially carrying out front rinsing under the view of a stereoscope and in an ultrasonic cleaner, carrying out rear fixing, rear rinsing and step-by-step gradient dehydration, putting the white ants into a specially-made filter paper cylinder, sealing the filter paper cylinder, putting the filter paper cylinder into a critical point drying frame, carrying out critical point drying, bonding samples close to a platform under the stereoscope, further dissecting target tissues of partial samples, carrying out secondary sample bonding, connecting the samples which are not subjected to secondary sample bonding with sample bonding adhesive tapes in a non-target observation region by virtue of a conductive silver adhesive, and carrying out all-direction gold sputtering after the conductive silver adhesive is dried. According to the scanning electron microscope sample processing method, multi-aspect technical problems in the background art that the surfaces of the samples are polluted, the samples are difficult to sink in fixation liquid and shrink to deform, different tissue parts of the samples are mutually shaded, and the samples are charged and discharged when being observed in an electron microscope are effectively solved, the cost for solving the problems is low, and the method has relatively high application value.

The invention provides a method for preparing scanning electron microscope samples from biological samples. The method comprises enabling a first antibody marked with first gold nanoparticles and a second antibody marked with second gold nanoparticles to contact with a biological sample after the biological sample is in resistance treatment; and then successively performing fixation, gradient dehydration and critical point drying. The shapes of the first gold nanoparticles are different from those of the second gold nanoparticles, and the first gold nanoparticles and the second gold nanoparticles are one or more from cylindrical gold nano bars, octahedral gold nanoparticles, spherical gold nanoparticles and arrow-shaped gold nanoparticles. The scanning electron microscope samples prepared by the method can accurately distinguish two types of different protein molecules in a low-vacuum mode.

The invention discloses a method for enhancing the contrast of micro-CT plant samples. The method comprises the following steps: 1) dissolving phosphotungstic acid in FAA fixative solution to obtain a phosphotungstic acid solution; 2) using the phosphotungstic acid solution to soak the plant parts to be tested for fixation and dyeing; 3) through the steps 2) The fixed and dyed plant parts are sequentially dehydrated and dried at the critical point of carbon dioxide, which can enhance the contrast of the micro-CT of the plant sample. Micro-CT scanning (Skyscan1172, Bruker Company) was performed on the sample dried at the critical point of carbon dioxide. The scanning voltage can be 41V-59V, and the resolution can be 0.56-1.76μm. , the contrast of plant samples in different parts has been greatly improved, and the contrast of the cytoplasm-rich and protein-rich parts such as magnolia flower buds has been improved more significantly.